Fellow time-nuts, Now a few days into the EFTF 2016 in York, I can report we are having some good fun. Attila get's to bounce his work against some good folks, and I get to bounce some of my ideas around too, with nice responce. I did my presentation today, and it went really smooth. I held a presentation on the use of least-square methods to estimate phase, frequency and parabolic variance (PVAR), work I have done together with Francoise Vernotte and Enrico Rubiola. It was interesting as two counter manufactures have approached me wishing to implement this. What I have done is to re-articulate the work of Francois and Enrico, but in a form more adaptable to accumulation in FPGA and then continue in software while maintaining the least-square properties as you extend the tau-length in further software decimation of the data. The algorithm I present allows for decimation and from the decimated blocks one can then produce any integer tau-multiple as one wish. This allows million of samples per second to be collected in FPGA and further processing at moderate rate and with much reduced memory needs. It avoids the biasing of deviation as otherwise often seen, I've spotted it in several posters and one presentation here. I wave my finger mumbling something about bad science! :) I naturally avoid doing such mistakes myself while presenting a solution that does it proper. I got some good questions and in general good response. The real-time least-square estimation method that is the underlying method of what I do is quite useful in many contexts. One interesting poster from Justervesenet (Norways National Meterology Institute) addressed some odd characteristics of the Keysight 53230A counter and the way it process data. It have shown several problems, and part of the research was done after borrowing a counter from a time-nuts. :) I found a USNO guy looking at it, thinking about it, and I brought Enrico and Francois to is, as they have been active in analyzing behavior of the lambda and omega counters. Cheers, Magnus

> One interesting poster from Justervesenet (Norways National Meterology > Institute) addressed some odd characteristics of the Keysight 53230A > counter and the way it process data. It have shown several problems, and > part of the research was done after borrowing a counter from a > time-nuts. :) I found a USNO guy looking at it, thinking about it, and I > brought Enrico and Francois to is, as they have been active in analyzing > behavior of the lambda and omega counters. > > Cheers, > Magnus Magnus, Thanks for that EFTF update. Will your paper be online somewhere so we can read it? About odd characteristics in the 53230A, please also see: "... Frequency Error near the Reference Frequency Harmonics" http://cp.literature.agilent.com/litweb/pdf/5990-9189EN.pdf Does it relate at all to these discussions: https://www.febo.com/pipermail/time-nuts/2012-October/070737.html https://www.febo.com/pipermail/time-nuts/2015-February/091026.html https://www.febo.com/pipermail/time-nuts/2015-February/091047.html https://www.febo.com/pipermail/time-nuts/2015-March/091056.html /tvb

-------- In message <CE09AD3ED0904D42AD019AED4ADD7DBB@pc52>, "Tom Van Baak" writes: >About odd characteristics in the 53230A, please also see: > >"... Frequency Error near the Reference Frequency Harmonics" >http://cp.literature.agilent.com/litweb/pdf/5990-9189EN.pdf >Does it relate at all to these discussions: I remember reporting on t-n a simple experiment I did on my HP5370: TI, START=REF, STOP=REF+phase_offset (I used my HP3336 to deliver the phase_offset.) Then plot the TI versus the phase_offset. Ideally it should be a straight line, in practice it is anything but. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

Tom, On 04/07/2016 02:55 AM, Tom Van Baak wrote: >> One interesting poster from Justervesenet (Norways National Meterology >> Institute) addressed some odd characteristics of the Keysight 53230A >> counter and the way it process data. It have shown several problems, and >> part of the research was done after borrowing a counter from a >> time-nuts. :) I found a USNO guy looking at it, thinking about it, and I >> brought Enrico and Francois to is, as they have been active in analyzing >> behavior of the lambda and omega counters. >> >> Cheers, >> Magnus > > Magnus, > > Thanks for that EFTF update. Will your paper be online somewhere so we can read it? EFTF papers have a tradition of becoming online, so that will not be a problem. Work on a full-length journal version is being done, so you can get more flesh on the bones. Don't worry, it will be available. :) > About odd characteristics in the 53230A, please also see: > > "... Frequency Error near the Reference Frequency Harmonics" > http://cp.literature.agilent.com/litweb/pdf/5990-9189EN.pdf > > Does it relate at all to these discussions: > > https://www.febo.com/pipermail/time-nuts/2012-October/070737.html > https://www.febo.com/pipermail/time-nuts/2015-February/091026.html > https://www.febo.com/pipermail/time-nuts/2015-February/091047.html > https://www.febo.com/pipermail/time-nuts/2015-March/091056.html I remember, but thanks for the pointers. :) Cheers, Magnus